Here, we analyze the variability in the diet composition and feeding intensity between sexes, size classes and degrees of sexual maturity of the squid Illex argentinus in the Argentine-Uruguayan Common Fishing Zone (AUCFZ). The stomach content of 6369 specimens of Illex argentinus was macroscopically examined during september and october of 1998 onboard three jigging vessels. The dominant prey item in each stomach (diet based on the dominant prey item, DBDPI) was determined. The results obtained in this study show that: (i) the diet composition of Illex argentinus in the AUCFZ is dominated by crustaceans, (ii) the low level of cannibalism observed suggest that the availability of food in the study area is adequate, (iii) the feeding habits for both sexes of Illex argentinus are similar, (iv) the diet composition of Illex argentinus is determined by the size of the individuals, and (v) it was not possible to identify the more influent factor of the feeding intensity in this species (body size, sexual maturity)